1. Field of Invention
This invention relates generally to providing an optical indication in the eyepiece of a microscope that is representative of the location at which a specimen is manipulated (e.g. by a laser beam during microsurgery), and, in particular, to an objective assembly for use with a microscope that provides an optical indication in the eyepiece of a microscope when a specimen is micro-manipulated during laser beam surgery.
2. Description of Related Arts
Recent advances in biology and medicine have led to the development of laser beam microsurgery on cells. The laser beam is well adapted to micro-manipulation of small objects, such as single cells or organelles. It provides the advantage of non-contact ablation, volatilization, sterilization and denaturing, cutting, and other forms of thermal and actinic-light treatment. The four parameters of focal spot size, laser wavelength, pulse duration, and laser power, provide a variety of regimes suitable for different applications. One example of a use of laser beam microsurgery is the application of laser beams to the treatment of a mammalian oocyte and embryo. However, laser beam microsurgery or manipulation in a number of inverted or upright microscopes can be utilized for many different surgical, medical or research applications.
In accordance with commonly practiced methods of laser beam microsurgery, the person conducting the microsurgery watches a screen displaying the sample and an indication of where the laser beam would be applied on the sample. One indication of the position of the laser beam on the sample is the formation sometimes of a plurality of isothermal contours on the specimen that evidence the range of effect the heat from the laser beam may have. Examples of such isothermal contours are described in U.S. Pat. No. 7,359,116 and U.S. patent application Ser. No. 11/764,064, which are incorporated by reference as if fully set forth herein. Accordingly, providing an optical indication in the eyepiece of a microscope of the position at which the specimen is manipulated would be highly desirable.